pub fn add(left: usize, right: usize) -> usize {
    left + right
}

#[cfg(test)]
mod tests {

    #[test]
    fn it_works() {
        let res = "11foo1bar11".trim_matches('1');
        println!("{}", res);
        // assert_eq!("11foo1bar11".trim_matches('1'), "foo1bar");
    }
}
